Inglis J T, Meunier S, Leeper J B, Burke D, Gandevia S C
School of Human Kinetics, The University of British Columbia, Faculty of Education, Canada.
Exp Brain Res. 1997 Jun;115(1):165-8. doi: 10.1007/pl00005677.
The human thumb is controlled by a muscle, flexor pollicis longus (FPL), that is unique among mammals and contributes to manual dexterity. The present study sought to define whether the spinal reflex circuitry for this muscle differed from that for an adjacent muscle (flexor carpi radialis, FCR). In peri-stimulus time histograms, short-latency, largely monosynaptic excitation produced by median nerve stimulation was significantly less frequent and significantly smaller for FPL motor units than FCR motor units. Thus the motoneurone pools of adjacent muscles differ in their spinal reflex accessibility. The reflex control of FPL may thus be achieved by supraspinal pathways rather than the traditional monosynaptic arc.
人类拇指由拇长屈肌（FPL）控制，该肌肉在哺乳动物中独一无二，有助于手部灵活性。本研究旨在确定该肌肉的脊髓反射回路是否与相邻肌肉（桡侧腕屈肌，FCR）的不同。在刺激周围时间直方图中，正中神经刺激产生的短潜伏期、主要为单突触的兴奋，在FPL运动单位中比FCR运动单位的频率显著更低且幅度显著更小。因此，相邻肌肉的运动神经元池在脊髓反射的可及性方面存在差异。FPL的反射控制可能通过脊髓上通路而非传统的单突触弧来实现。
